Marengo C, Mbikay M, Weber J, Thirion J P
J Virol. 1981 Apr;38(1):184-90. doi: 10.1128/JVI.38.1.184-190.1981.
Hpt-13 is a Chinese hamster cell line deficient in hypoxanthine phosphoribosyltransferase (EC 2.4.2.8) and sensitive to a medium containing 10(-4) M hypoxanthine, 5.5 X 10(-6) M aminopterin, and 10(-4) M thymidine. In this cell line there is a high incidence of cells resistant to this selective medium after an incubation with either ethyl methane sulfonate or adenovirus type 2 complete virions or their incomplete particles. The rate of reversion in the presence of these agents was 34-fold higher with ethyl methane sulfonate and 2.5- to 5.6-fold higher with adenovirus particles than the spontaneous rate of reversion. The revertant phenotypes were stable for many generations without selective pressure. All of the revertants tested recovered the hypoxanthine phosphoribosyltransferase activity. Most of them, however, carried an enzyme of lower activity and faster electrophoretic mobility than that of the wild type. The preferential reversion to this type of enzyme was observed among spontaneous revertants as well as among those induced by mutagenesis with ethyl methane sulfonate or exposure to viral particles. Our results suggest that adenovirus particles and ethyl methane sulfonate induce mutations at the hpt locus of Hpt-13 cells through similar mechanisms.
Hpt - 13是一种中国仓鼠细胞系，缺乏次黄嘌呤磷酸核糖转移酶（EC 2.4.2.8），并且对含有10⁻⁴M次黄嘌呤、5.5×10⁻⁶M氨甲蝶呤和10⁻⁴M胸腺嘧啶的培养基敏感。在该细胞系中，用甲磺酸乙酯或2型腺病毒完整病毒体或其不完整颗粒孵育后，对这种选择性培养基产生抗性的细胞发生率很高。在这些试剂存在下，甲磺酸乙酯诱导的回复突变率比自发回复突变率高34倍，腺病毒颗粒诱导的回复突变率比自发回复突变率高2.5至5.6倍。在没有选择压力的情况下，回复突变表型在许多代中都是稳定的。所有测试的回复突变体都恢复了次黄嘌呤磷酸核糖转移酶活性。然而，它们中的大多数携带的酶活性低于野生型，并且电泳迁移率比野生型快。在自发回复突变体以及由甲磺酸乙酯诱变或暴露于病毒颗粒诱导的回复突变体中都观察到了向这种类型酶的优先回复突变。我们的结果表明，腺病毒颗粒和甲磺酸乙酯通过相似的机制在Hpt - 13细胞的hpt基因座诱导突变。
